TAMPA — A severe winter storm rolling across the South on Tuesday and Wednesday held an icy grip on Interstate 10, closing the highway across Florida’s Panhandle and sending truck traffic and other motorists scrambling for alternate routes.

The interstate remained closed from the Florida-Alabama line east to Tallahassee for most of Wednesday. Traffic was rerouted to U.S. 90, enabling drivers to get through — if at a slower pace.

“Whenever we have to close an interstate, we always have an alternative,” said Florida Highway Patrol Capt. Nancy Rasmussen. “There are roadways they can cross, so it won’t prevent anyone from getting down to South Florida. It’s just that instead of driving 70, they’ll be going 45 or 55 through all the towns and such.”

Trucking companies were among those hardest hit by the wild weather. Tampa-based trucking company WES-FLO Inc. on Wednesday had six trucks idling in cities including Mobile, Ala., Atlanta and the Florida Panhandle town of Marianna, unable to complete their hauls. A few were heading to or returning from Texas, operations manager Jim Perry said.

Meantime, a few other trucks sat idle in his Tampa yard because it was fruitless to send them out on the road, Perry said. The bad weather is hitting his company in the pocketbook, he said, because he is paying his drivers’ wages as they sit idle. So far, the delays are not costing him customers.

“My customers are pretty much understanding that there’s nothing we can do,” Perry said.

Lakeland-based Publix Super Markets was trying to keep stores in affected areas open for as long as it was safe for customers and employees to be on the roads, Publix spokesman Brian West said.

He said he couldn’t disclose whether the grocery chain closed any stores early because of the weather.

Crews from Florida’s Department of Transportation and the Florida Highway Patrol on Wednesday morning dumped sand on the interstate’s frozen bridges and on other icy bridges in the Panhandle.

The highway patrol issued a warning Wednesday, ticking off a list of roads closed in northwest Florida. Earlier, the patrol had issued an emergency weather alert to motorists, warning of possible icy and snowy road conditions.

Getting south of Tallahassee was the key.

Meteorologist Robert Garcia with the National Weather Service in Ruskin said the worst weather in central Florida, as far south as Fort Myers, would be temperatures in the 40s and light rain, but no freezing precipitation.

“As you get on toward I-10, ... I’ve seen a few reports of sleet and freezing rain in Tallahassee,” he said, but nothing like that farther south.